Branches of the tree of life at risk of trade

Almost 20% of terrestrial vertebrate species - 5,500 species - are being traded, and up to 3000 more are at risk of being traded in the future, a new study has shown...

David Edwards, from the University of Sheffield, one of the lead researchers on the project, summarised the work as “showing that there is an enormous diversity of species being traded, and that we hope that our prediction of potential species to be traded represents a watchlist that can help conservationists, conservation NGOs and governments to be looking out for the potential risks for those species whose trade may emerge in the future.”

By using the phylogeny of species - how species relate to each other in the tree of life - the researchers were able to find not just individual species that are being traded, but also groups of species that are of interest to wildlife trade, whether for pet or product purposes.

TheTangaratanagers are one such example. Many species in this group of birds have very colourful feathers, and so they are sought after as pets. While at the moment only some of the species are being traded, David and his colleagues anticipate that the other species in theTangaragenus are at risk in the future, especially if the currently traded species are heading towards extinction.

Of the over 31,500 species of birds, mammals, amphibians and reptiles, the researchers predict that around 300 species will be affected by trade in the future with a 95% probability, and up to 3,000 species with a 90% probability.

Unfortunately, it’s not only the illegal trade that is driving the extinction of large swaths of the tree of life - legal trade plays a large role as well.

“For many tropical species we lack the information and the capacity to say what a sustainable harvest is. Which means that we see legal trade, and then at some point we realise a species has been reduced considerably, and we become concerned,” warns Edwards.

The researchers also looked at where the terrestrial vertebrate species were coming from.

The diversity in trade broadly followed the diversity in species overall, with the tropics being generally the most species-diverse areas on the planet. For example, the Amazonian forest was the main hotspot for amphibians, while sub-Saharan Africa and South-East Asia had a high diversity of trade for mammals.

Understanding what species are likely to be traded next, and where the traded species are coming from, could be very important to focus conservation efforts and avoid further species extinction. Being able to anticipate rather than react to new species entering trade could have a profound effect on better managing global wildlife trade.